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87-539: CASC was officially established in July 1999 as part of a Chinese government reform drive, having previously been one part of the former China Aerospace Corporation. Various incarnations of the program date back to 1956. Along with space and defense manufacture, CASC also produces machinery , chemicals , communications equipment, transportation equipment, computers , medical care products and environmental protection equipment. CASC provides commercial launch services to

174-640: A pipe threader . It remains in common use for repair of existing "galv" systems and to satisfy building code non-combustibility requirements typically found in hotels, apartment buildings and other commercial applications. It is also extremely durable and resistant to mechanical abuse. Black lacquered steel pipe is the most widely used pipe material for fire sprinklers and natural gas. Most typical single family home systems will not require supply piping larger than 3 ⁄ 4 inch (19 mm) due to expense as well as steel piping's tendency to become obstructed from internal rusting and mineral deposits forming on

261-502: A (near-) synonym both by Harris and in later language derives ultimately (via Old French ) from Latin ingenium 'ingenuity, an invention'. The hand axe , made by chipping flint to form a wedge , in the hands of a human transforms force and movement of the tool into a transverse splitting forces and movement of the workpiece. The hand axe is the first example of a wedge , the oldest of the six classic simple machines , from which most machines are based. The second oldest simple machine

348-738: A building's plumbing system. They are considered to be "fixtures", in that they are semi-permanent parts of buildings, not usually owned or maintained separately. Plumbing fixtures are seen by and designed for the end-users . Some examples of fixtures include water closets (also known as toilets ), urinals , bidets , showers , bathtubs , utility and kitchen sinks , drinking fountains , ice makers , humidifiers, air washers , fountains , and eye wash stations. Threaded pipe joints are sealed with thread seal tape or pipe dope . Many plumbing fixtures are sealed to their mounting surfaces with plumber's putty . Plumbing equipment includes devices often behind walls or in utility spaces which are not seen by

435-576: A copper waste pipe. The word "plumber" dates from the Roman Empire . The Latin for lead is plumbum . Roman roofs used lead in conduits and drain pipes and some were also covered with lead. Lead was also used for piping and for making baths. Plumbing reached its early apex in ancient Rome , which saw the introduction of expansive systems of aqueducts , tile wastewater removal, and widespread use of lead pipes . The Romans used lead pipe inscriptions to prevent water theft . With

522-554: A decade ago. This has led to an increase in plumbing regulatory issues not covered under current policy, and as such, many policies are currently being updated to cover these more modern issues. The updates include changed to the minimum experience and training requirements for licensing, additional work standards for new and more specific kinds of plumbing, as well as adopting the Plumbing Code of Australia into state regulations in an effort to standardise plumbing regulations across

609-565: A heavy duty pumper truck designed to vacuum raw sewage. Bacteria have been shown to live in "premises plumbing systems". The latter refers to the "pipes and fixtures within a building that transport water to taps after it is delivered by the utility". Community water systems have been known for centuries to spread waterborne diseases like typhoid and cholera. However, "opportunistic premises plumbing pathogens" have been recognized only more recently: Legionella pneumophila , discovered in 1976, Mycobacterium avium , and Pseudomonas aeruginosa are

696-429: A layer of plaque prevented the water contacting the lead itself. What often causes confusion is the large amount of evidence of widespread lead poisoning, particularly amongst those who would have had easy access to piped water, an unfortunate result of lead being used in cookware and as an additive to processed food and drink (for example as a preservative in wine). Roman lead pipe inscriptions provided information on

783-401: A lever is modeled as a hinged or revolute joint . Wheel: The wheel is an important early machine, such as the chariot . A wheel uses the law of the lever to reduce the force needed to overcome friction when pulling a load. To see this notice that the friction associated with pulling a load on the ground is approximately the same as the friction in a simple bearing that supports the load on

870-420: A machine is "a device for applying power or changing its direction."McCarthy and Soh describe a machine as a system that "generally consists of a power source and a mechanism for the controlled use of this power." Human and animal effort were the original power sources for early machines. Waterwheel: Waterwheels appeared around the world around 300 BC to use flowing water to generate rotary motion, which

957-470: A machine provides a way to understand the performance of devices ranging from levers and gear trains to automobiles and robotic systems. The German mechanician Franz Reuleaux wrote, "a machine is a combination of resistant bodies so arranged that by their means the mechanical forces of nature can be compelled to do work accompanied by certain determinate motion." Notice that forces and motion combine to define power . More recently, Uicker et al. stated that

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1044-838: A mechanical system is assembled from components called machine elements . These elements provide structure for the system and control its movement. The structural components are, generally, the frame members, bearings, splines, springs, seals, fasteners and covers. The shape, texture and color of covers provide a styling and operational interface between the mechanical system and its users. The assemblies that control movement are also called " mechanisms ." Mechanisms are generally classified as gears and gear trains , which includes belt drives and chain drives , cam and follower mechanisms, and linkages , though there are other special mechanisms such as clamping linkages, indexing mechanisms , escapements and friction devices such as brakes and clutches . The number of degrees of freedom of

1131-500: A mechanism, or its mobility, depends on the number of links and joints and the types of joints used to construct the mechanism. The general mobility of a mechanism is the difference between the unconstrained freedom of the links and the number of constraints imposed by the joints. It is described by the Chebychev–Grübler–Kutzbach criterion . The transmission of rotation between contacting toothed wheels can be traced back to

1218-464: A method to plasticize PVC, making it easier to process. PVC pipe began to be manufactured in the 1940s and was in wide use for Drain-Waste-Vent piping during the reconstruction of Germany and Japan following WWII. In the 1950s, plastics manufacturers in Western Europe and Japan began producing acrylonitrile butadiene styrene (ABS) pipe. The method for producing cross-linked polyethylene (PEX)

1305-412: A point farther from the pivot is greater than the velocity of a point near the pivot, forces applied far from the pivot are amplified near the pivot by the associated decrease in speed. If a is the distance from the pivot to the point where the input force is applied and b is the distance to the point where the output force is applied, then a/b is the mechanical advantage of the lever. The fulcrum of

1392-430: A pressure vessel; the expanding steam drives a piston or a turbine. This principle can be seen in the aeolipile of Hero of Alexandria. This is called an external combustion engine . An automobile engine is called an internal combustion engine because it burns fuel (an exothermic chemical reaction) inside a cylinder and uses the expanding gases to drive a piston . A jet engine uses a turbine to compress air which

1479-534: A programmable drum machine , where they could be made to play different rhythms and different drum patterns. During the Renaissance , the dynamics of the Mechanical Powers , as the simple machines were called, began to be studied from the standpoint of how much useful work they could perform, leading eventually to the new concept of mechanical work . In 1586 Flemish engineer Simon Stevin derived

1566-432: A relatively large surface area allows the bacteria to form a biofilm , which protects them from disinfection. Much of the plumbing work in populated areas is regulated by government or quasi-government agencies due to the direct impact on the public's health, safety, and welfare. Plumbing installation and repair work on residences and other buildings generally must be done according to plumbing and building codes to protect

1653-459: A specific application of output forces and movement, (iii) a controller with sensors that compare the output to a performance goal and then directs the actuator input, and (iv) an interface to an operator consisting of levers, switches, and displays. This can be seen in Watt's steam engine in which the power is provided by steam expanding to drive the piston. The walking beam, coupler and crank transform

1740-646: A system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement. They can also include computers and sensors that monitor performance and plan movement, often called mechanical systems . Renaissance natural philosophers identified six simple machines which were the elementary devices that put a load into motion, and calculated the ratio of output force to input force, known today as mechanical advantage . Modern machines are complex systems that consist of structural elements, mechanisms and control components and include interfaces for convenient use. Examples include:

1827-403: A wide range of vehicles , such as trains , automobiles , boats and airplanes ; appliances in the home and office, including computers, building air handling and water handling systems ; as well as farm machinery , machine tools and factory automation systems and robots . The English word machine comes through Middle French from Latin machina , which in turn derives from

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1914-542: Is SASAC, the company's headquarters are still in Beijing, the business areas remained the same and nothing changed for the staff either. In 2021, China's 14th five year plan included two low Earth orbit satellite constellations named “GW” featuring nearly 13,000 satellites was in development. The "directly subordinated units" of the China Aerospace Science and Technology Corporation are: In 2006

2001-412: Is a matter of sizing. For instance, PVC pipe for plumbing applications and galvanized steel pipe are measured in iron pipe size (IPS). Copper tube, CPVC , PeX and other tubing is measured nominally, basically an average diameter. These sizing schemes allow for universal adaptation of transitional fittings. For instance, 1/2" PeX tubing is the same size as 1/2" copper tubing. 1/2" PVC on the other hand

2088-410: Is burned with fuel so that it expands through a nozzle to provide thrust to an aircraft , and so is also an "internal combustion engine." Power plant: The heat from coal and natural gas combustion in a boiler generates steam that drives a steam turbine to rotate an electric generator . A nuclear power plant uses heat from a nuclear reactor to generate steam and electric power . This power

2175-423: Is called the cam (also see cam shaft ) and the link that is driven through the direct contact of their surfaces is called the follower. The shape of the contacting surfaces of the cam and follower determines the movement of the mechanism. A linkage is a collection of links connected by joints. Generally, the links are the structural elements and the joints allow movement. Perhaps the single most useful example

2262-603: Is distributed through a network of transmission lines for industrial and individual use. Motors: Electric motors use either AC or DC electric current to generate rotational movement. Electric servomotors are the actuators for mechanical systems ranging from robotic systems to modern aircraft . Fluid Power: Hydraulic and pneumatic systems use electrically driven pumps to drive water or air respectively into cylinders to power linear movement . Electrochemical: Chemicals and materials can also be sources of power. They may chemically deplete or need re-charging, as

2349-401: Is made by chipping stone, generally flint, to form a bifacial edge, or wedge . A wedge is a simple machine that transforms lateral force and movement of the tool into a transverse splitting force and movement of the workpiece. The available power is limited by the effort of the person using the tool, but because power is the product of force and movement, the wedge amplifies the force by reducing

2436-486: Is not the same size as 1/2" tubing, and therefore requires either a threaded male or female adapter to connect them. When used in agricultural irrigation, the singular form "pipe" is often used as a plural. Pipe is available in rigid joints , which come in various lengths depending on the material. Tubing, in particular copper, comes in rigid hard tempered joints or soft tempered (annealed) rolls. PeX and CPVC tubing also comes in rigid joints or flexible rolls. The temper of

2523-406: Is rarely used today for new construction residential plumbing. Steel pipe has National Pipe Thread (NPT) standard tapered male threads, which connect with female tapered threads on elbows, tees, couplers, valves , and other fittings. Galvanized steel (often known simply as " galv " or " iron " in the plumbing trade) is relatively expensive, and difficult to work with due to weight and requirement of

2610-420: Is the case with batteries , or they may produce power without changing their state, which is the case for solar cells and thermoelectric generators . All of these, however, still require their energy to come from elsewhere. With batteries, it is the already existing chemical potential energy inside. In solar cells and thermoelectrics, the energy source is light and heat respectively. The mechanism of

2697-421: Is the planar four-bar linkage . However, there are many more special linkages: A planar mechanism is a mechanical system that is constrained so the trajectories of points in all the bodies of the system lie on planes parallel to a ground plane. The rotational axes of hinged joints that connect the bodies in the system are perpendicular to this ground plane. A spherical mechanism is a mechanical system in which

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2784-405: Is true that the trade still remains virtually ungoverned; there are no systems in place to monitor or control the activities of unqualified plumbers or those home owners who choose to undertake installation and maintenance works themselves, despite the health and safety issues which arise from such works when they are undertaken incorrectly; see Health Aspects of Plumbing (HAP) published jointly by

2871-598: Is typically formed via casting or welding , whereas a tube is made through extrusion . Pipe normally has thicker walls and may be threaded or welded, while tubing is thinner-walled and requires special joining techniques such as brazing , compression fitting , crimping , or for plastics, solvent welding . These joining techniques are discussed in more detail in the piping and plumbing fittings article. Galvanized steel potable water supply and distribution pipes are commonly found with nominal pipe sizes from 3 ⁄ 8 inch (9.5 mm) to 2 inches (51 mm). It

2958-516: The Antikythera mechanism of Greece and the south-pointing chariot of China . Illustrations by the renaissance scientist Georgius Agricola show gear trains with cylindrical teeth. The implementation of the involute tooth yielded a standard gear design that provides a constant speed ratio. Some important features of gears and gear trains are: A cam and follower is formed by the direct contact of two specially shaped links. The driving link

3045-450: The Fall of Rome both water supply and sanitation stagnated—or regressed—for well over 1,000 years. Improvement was very slow, with little effective progress made until the growth of modern densely populated cities in the 1800s. During this period, public health authorities began pressing for better waste disposal systems to be installed, to prevent or control epidemics of disease. Earlier,

3132-517: The Greek ( Doric μαχανά makhana , Ionic μηχανή mekhane 'contrivance, machine, engine', a derivation from μῆχος mekhos 'means, expedient, remedy' ). The word mechanical (Greek: μηχανικός ) comes from the same Greek roots. A wider meaning of 'fabric, structure' is found in classical Latin, but not in Greek usage. This meaning is found in late medieval French, and is adopted from

3219-664: The Hittite city of Hattusa . They had easily detachable and replaceable segments, and allowed for cleaning. Standardized earthen plumbing pipes with broad flanges making use of asphalt for preventing leakages appeared in the urban settlements of the Indus Valley civilization by 2700 BC. Copper piping appeared in Egypt by 2400 BCE, with the Pyramid of Sahure and adjoining temple complex at Abusir , found to be connected by

3306-795: The People's Liberation Army , which included CASC. In August 2022, CASC's 9th Academy 771 and 772 Research Institutes were added to the United States Department of Commerce 's Entity List . Machinery A machine is a physical system that uses power to apply forces and control movement to perform an action. The term is commonly applied to artificial devices, such as those employing engines or motors, but also to natural biological macromolecules, such as molecular machines . Machines can be driven by animals and people , by natural forces such as wind and water , and by chemical , thermal , or electrical power, and include

3393-584: The Twelfth Dynasty (1991–1802 BC). The screw , the last of the simple machines to be invented, first appeared in Mesopotamia during the Neo-Assyrian period (911–609) BC. The Egyptian pyramids were built using three of the six simple machines, the inclined plane, the wedge, and the lever. Three of the simple machines were studied and described by Greek philosopher Archimedes around

3480-891: The World Health Organization (WHO) and the World Plumbing Council (WPC) . WPC has subsequently appointed a representative to the World Health Organization to take forward various projects related to Health Aspects of Plumbing. In the United States, plumbing codes and licensing are generally controlled by state and local governments. At the national level, the Environmental Protection Agency has set guidelines about what constitutes lead -free plumbing fittings and pipes, in order to comply with

3567-497: The lever , pulley and screw as simple machines . By the time of the Renaissance this list increased to include the wheel and axle , wedge and inclined plane . The modern approach to characterizing machines focusses on the components that allow movement, known as joints . Wedge (hand axe): Perhaps the first example of a device designed to manage power is the hand axe , also called biface and Olorgesailie . A hand axe

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3654-557: The 1920s in the United States, although lead pipes were approved by national plumbing codes into the 1980s, and lead was used in plumbing solder for drinking water until it was banned in 1986. Drain and vent lines are made of plastic, steel, cast iron, or lead. In addition to lengths of pipe or tubing, pipe fittings such as valves, elbows, tees, and unions. are used in plumbing systems. Pipe and fittings are held in place with pipe hangers and strapping . Plumbing fixtures are exchangeable devices that use water and can be connected to

3741-516: The 3rd century BC: the lever, pulley and screw. Archimedes discovered the principle of mechanical advantage in the lever. Later Greek philosophers defined the classic five simple machines (excluding the inclined plane) and were able to roughly calculate their mechanical advantage. Hero of Alexandria ( c.  10 –75 AD) in his work Mechanics lists five mechanisms that can "set a load in motion"; lever, windlass , pulley, wedge, and screw, and describes their fabrication and uses. However,

3828-551: The French into English in the mid-16th century. In the 17th century, the word machine could also mean a scheme or plot, a meaning now expressed by the derived machination . The modern meaning develops out of specialized application of the term to stage engines used in theater and to military siege engines , both in the late 16th and early 17th centuries. The OED traces the formal, modern meaning to John Harris ' Lexicon Technicum (1704), which has: The word engine used as

3915-622: The Greeks' understanding was limited to statics (the balance of forces) and did not include dynamics (the tradeoff between force and distance) or the concept of work . The earliest practical wind-powered machines, the windmill and wind pump , first appeared in the Muslim world during the Islamic Golden Age , in what are now Iran, Afghanistan, and Pakistan, by the 9th century AD. The earliest practical steam-powered machine

4002-533: The Muslim world. A music sequencer , a programmable musical instrument , was the earliest type of programmable machine. The first music sequencer was an automated flute player invented by the Banu Musa brothers, described in their Book of Ingenious Devices , in the 9th century. In 1206, Al-Jazari invented programmable automata / robots . He described four automaton musicians, including drummers operated by

4089-709: The Plumbing Regulations 2008 and the Plumbing Code of Australia, pertains to plumbing. Each Government at the state level has their own Authority and regulations in place for licensing plumbers. They are also responsible for the interpretation, administration and enforcement of the regulations outlined in the NCC. These Authorities are usually established for the sole purpose of regulating plumbing activities in their respective states/territories. However, several state level regulation acts are quite outdated, with some still operating on local policies introduced more than

4176-790: The UK by the Standard Dimension Ratio (SDR), defined as the ratio of the pipe diameter to its wall thickness. Pipe wall thickness increases with schedule, and is available in schedules 20, 40, 80, and higher in special cases. The schedule is largely determined by the operating pressure of the system, with higher pressures commanding greater thickness. Copper tubing is available in four wall thicknesses: type DWV (thinnest wall; only allowed as drain pipe per UPC), type 'M' (thin; typically only allowed as drain pipe by IPC code), type 'L' (thicker, standard duty for water lines and water service), and type 'K' (thickest, typically used underground between

4263-619: The US Department of the Treasury accused Great Wall Industry and its partners of playing a lead role in the development of the Fateh missile system , as Iran had no previous experience with solid-fueled ballistic missiles. In November 2020, U.S. President Donald Trump issued an executive order prohibiting U.S. companies and individuals owning shares in companies that the United States Department of Defense has listed as having links to

4350-525: The US during the 20th century. These pipes (used in place of corrugated iron or reinforced concrete pipes) were made of sections cut from short lengths of wood. Locking of adjacent rings with hardwood dowel pins produced a flexible structure. About 100,000 feet of these wooden pipes were installed during WW2 in drainage culverts, storm sewers and conduits, under highways and at army camps, naval stations, airfields and ordnance plants. Cast iron and ductile iron pipe

4437-409: The axle of a wheel. However, the wheel forms a lever that magnifies the pulling force so that it overcomes the frictional resistance in the bearing. The classification of simple machines to provide a strategy for the design of new machines was developed by Franz Reuleaux , who collected and studied over 800 elementary machines. He recognized that the classical simple machines can be separated into

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4524-610: The bodies in the system form lines in space that do not intersect and have distinct common normals. A flexure mechanism consists of a series of rigid bodies connected by compliant elements (also known as flexure joints) that is designed to produce a geometrically well-defined motion upon application of a force. Plumbing Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes , valves , plumbing fixtures , tanks , and other apparatuses to convey fluids. Heating and cooling (HVAC), waste removal , and potable water delivery are among

4611-411: The bodies move in a way that the trajectories of points in the system lie on concentric spheres. The rotational axes of hinged joints that connect the bodies in the system pass through the center of these circle. A spatial mechanism is a mechanical system that has at least one body that moves in a way that its point trajectories are general space curves. The rotational axes of hinged joints that connect

4698-431: The copper, whether it is a rigid joint or flexible roll, does not affect the sizing. The thicknesses of the water pipe and tube walls can vary. Because piping and tubing are commodities, having a greater wall thickness implies higher initial cost. Thicker walled pipe generally implies greater durability and higher pressure tolerances. Pipe wall thickness is denoted by various schedules or for large bore polyethylene pipe in

4785-569: The country. In Norway, new domestic plumbing installed since 1997 has had to satisfy the requirement that it should be easily accessible for replacement after installation. This has led to the development of the pipe-in-pipe system as a de facto requirement for domestic plumbing. In the United Kingdom the professional body is the Chartered Institute of Plumbing and Heating Engineering (educational charity status) and it

4872-416: The dangers of lead poisoning . At this time, copper piping was introduced as a better and safer alternative to lead pipes. The major categories of plumbing systems or subsystems are: A water pipe is a pipe or tube , frequently made of plastic or metal, that carries pressurized and treated fresh water to a building (as part of a municipal water system ), as well as inside the building. Lead

4959-578: The double acting steam engine practical. The Boulton and Watt steam engine and later designs powered steam locomotives , steam ships , and factories . The Industrial Revolution was a period from 1750 to 1850 where changes in agriculture, manufacturing, mining, transportation, and technology had a profound effect on the social, economic and cultural conditions of the times. It began in the United Kingdom , then subsequently spread throughout Western Europe , North America , Japan , and eventually

5046-434: The dramatic increase in the price of copper, resulting in increased demand for alternative products including PEX and stainless steel . Plastic pipe is in wide use for domestic water supply and drain-waste-vent (DWV) pipe. Principal types include: Polyvinyl chloride (PVC) was produced experimentally in the 19th century but did not become practical to manufacture until 1926, when Waldo Semon of BF Goodrich Co. developed

5133-527: The early 20th century and remain in many households. Lead-tin alloy solder was commonly used to join copper pipes , but modern practice uses tin-antimony alloy solder instead in order to eliminate lead hazards. Despite the Romans' common use of lead pipes, their aqueducts rarely poisoned people. Unlike other parts of the world where lead pipes cause poisoning, the Roman water had so much calcium in it that

5220-457: The general public. It includes water meters , pumps , expansion tanks, back flow preventers , water filters , UV sterilization lights, water softeners , water heaters , heat exchangers , gauges, and control systems. There are many tools a plumber needs to do a good plumbing job. While many simple plumbing tasks can be completed with a few common hand held tools, other more complex jobs require specialised tools, designed specifically to make

5307-603: The inhabitants of the buildings and to ensure safe, quality construction to future buyers. If permits are required for work, plumbing contractors typically secure them from the authorities on behalf of home or building owners. In Australia, the national governing body for plumbing regulation is the Australian Building Codes Board . They are responsible for the creation of the National Construction Code (NCC), Volume 3 of which,

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5394-453: The inside of the pipe over time once the internal galvanizing zinc coating has degraded. In potable water distribution service, galvanized steel pipe has a service life of about 30 to 50 years, although it is not uncommon for it to be less in geographic areas with corrosive water contaminants. Copper pipe and tubing was widely used for domestic water systems in the latter half of the twentieth century. Demand for copper products has fallen due to

5481-616: The international market. By the end of 2013, the corporation has registered capital of CN¥294.02 billion and employs 170,000 people. In December 2017, the CASC was restructured from a state-owned enterprise (全民所有制企业) to a state-owned enterprise with limited liability (国有独资公司) with the approval of the State-owned Assets Supervision and Administration Commission of the State Council (SASAC). The sole shareholder

5568-591: The job easier. Specialized plumbing tools include pipe wrenches , flaring pliers , pipe vise, pipe bending machine, pipe cutter, dies , and joining tools such as soldering torches and crimp tools. New tools have been developed to help plumbers fix problems more efficiently. For example, plumbers use video cameras for inspections of hidden leaks or other problems; they also use hydro jets, and high pressure hydraulic pumps connected to steel cables for trench-less sewer line replacement. Flooding from excessive rain or clogged sewers may require specialized equipment, such as

5655-417: The lever, pulley and wheel and axle that are formed by a body rotating about a hinge, and the inclined plane, wedge and screw that are similarly a block sliding on a flat surface. Simple machines are elementary examples of kinematic chains or linkages that are used to model mechanical systems ranging from the steam engine to robot manipulators. The bearings that form the fulcrum of a lever and that allow

5742-529: The linear movement of the piston into rotation of the output pulley. Finally, the pulley rotation drives the flyball governor which controls the valve for the steam input to the piston cylinder. The adjective "mechanical" refers to skill in the practical application of an art or science, as well as relating to or caused by movement, physical forces, properties or agents such as is dealt with by mechanics . Similarly Merriam-Webster Dictionary defines "mechanical" as relating to machinery or tools. Power flow through

5829-454: The main and the meter). Wall thickness does not affect pipe or tubing size. 1/2" L copper has the same outer diameter as 1/2" K or M copper. The same applies to pipe schedules. As a result, a slight increase in pressure losses is realized due to a decrease in flowpath as wall thickness is increased. In other words, 1 foot of 1/2" L copper has slightly less volume than 1 foot of 1/2 M copper. Water systems of ancient times relied on gravity for

5916-758: The mechanical advantage of the inclined plane, and it was included with the other simple machines. The complete dynamic theory of simple machines was worked out by Italian scientist Galileo Galilei in 1600 in Le Meccaniche ("On Mechanics"). He was the first to understand that simple machines do not create energy , they merely transform it. The classic rules of sliding friction in machines were discovered by Leonardo da Vinci (1452–1519), but remained unpublished in his notebooks. They were rediscovered by Guillaume Amontons (1699) and were further developed by Charles-Augustin de Coulomb (1785). James Watt patented his parallel motion linkage in 1782, which made

6003-778: The most common uses for plumbing, but it is not limited to these applications. The word derives from the Latin for lead , plumbum , as the first effective pipes used in the Roman era were lead pipes . In the developed world, plumbing infrastructure is critical to public health and sanitation . Boilermakers and pipefitters are not plumbers although they work with piping as part of their trade and their work can include some plumbing. Plumbing originated during ancient civilizations, as they developed public baths and needed to provide potable water and wastewater removal for larger numbers of people. The Mesopotamians introduced

6090-435: The most commonly tracked bacteria, which people with depressed immunity can inhale or ingest and may become infected with. Some of the locations where these opportunistic pathogens can grow include faucets, shower heads, water heaters and along pipe walls. Reasons that favor their growth are "high surface-to-volume ratio, intermittent stagnation, low disinfectant residual, and warming cycles". A high surface-to-volume ratio, i.e.

6177-408: The movement. This amplification, or mechanical advantage is the ratio of the input speed to output speed. For a wedge this is given by 1/tanα, where α is the tip angle. The faces of a wedge are modeled as straight lines to form a sliding or prismatic joint . Lever: The lever is another important and simple device for managing power. This is a body that pivots on a fulcrum. Because the velocity of

6264-419: The output of one crank to the input of another. Additional links can be attached to form a six-bar linkage or in series to form a robot. A mechanical system manages power to accomplish a task that involves forces and movement. Modern machines are systems consisting of (i) a power source and actuators that generate forces and movement, (ii) a system of mechanisms that shape the actuator input to achieve

6351-540: The owner to prevent water theft. Wooden pipes were used in London and elsewhere during the 16th and 17th centuries. The pipes were hollowed-out logs which were tapered at the end with a small hole in which the water would pass through. The multiple pipes were then sealed together with hot animal fat. Wooden pipes were used in Philadelphia, Boston, and Montreal in the 1800s. Built-up wooden tubes were widely used in

6438-403: The primary elements of a machine. Starting with four types of joints, the rotary joint, sliding joint, cam joint and gear joint, and related connections such as cables and belts, it is possible to understand a machine as an assembly of solid parts that connect these joints called a mechanism . Two levers, or cranks, are combined into a planar four-bar linkage by attaching a link that connects

6525-467: The rest of the world. Starting in the later part of the 18th century, there began a transition in parts of Great Britain 's previously manual labour and draft-animal-based economy towards machine-based manufacturing. It started with the mechanisation of the textile industries, the development of iron-making techniques and the increased use of refined coal . The idea that a machine can be decomposed into simple movable elements led Archimedes to define

6612-644: The supply of water, using pipes or channels usually made of clay , lead , bamboo, wood, or stone. Hollowed wooden logs wrapped in steel banding were used for plumbing pipes, particularly water mains. Logs were used for water distribution in England close to 500 years ago. US cities began using hollowed logs in the late 1700s through the 1800s. Today, most plumbing supply pipe is made out of steel, copper, and plastic; most waste (also known as "soil") out of steel, copper, plastic, and cast iron. The straight sections of plumbing systems are called "pipes" or "tubes". A pipe

6699-433: The waste disposal system had consisted of collecting waste and dumping it on the ground or into a river. Eventually the development of separate, underground water and sewage systems eliminated open sewage ditches and cesspools . In post-classical Kilwa the wealthy enjoyed indoor plumbing in their stone homes. Most large cities today pipe solid wastes to sewage treatment plants in order to separate and partially purify

6786-436: The water, before emptying into streams or other bodies of water. For potable water use, galvanized iron piping was commonplace in the United States from the late 1800s until around 1960. After that period, copper piping took over, first soft copper with flared fittings, then with rigid copper tubing using soldered fittings. The use of lead for potable water declined sharply after World War II because of increased awareness of

6873-399: The wheel and axle and pulleys to rotate are examples of a kinematic pair called a hinged joint. Similarly, the flat surface of an inclined plane and wedge are examples of the kinematic pair called a sliding joint. The screw is usually identified as its own kinematic pair called a helical joint. This realization shows that it is the joints, or the connections that provide movement, that are

6960-457: The world to clay sewer pipes around 4000 BCE, with the earliest examples found in the Temple of Bel at Nippur and at Eshnunna , used to remove wastewater from sites, and capture rainwater, in wells. The city of Uruk contains the oldest known examples of brick constructed Latrines , constructed atop interconnecting fired clay sewer pipes, c.  3200 BCE . Clay pipes were later used in

7047-696: Was a steam jack driven by a steam turbine , described in 1551 by Taqi ad-Din Muhammad ibn Ma'ruf in Ottoman Egypt . The cotton gin was invented in India by the 6th century AD, and the spinning wheel was invented in the Islamic world by the early 11th century, both of which were fundamental to the growth of the cotton industry . The spinning wheel was also a precursor to the spinning jenny . The earliest programmable machines were developed in

7134-497: Was also developed in the 1950s. Plastic supply pipes have become increasingly common, with a variety of materials and fittings employed. Present-day water-supply systems use a network of high-pressure pumps, and pipes in buildings are now made of copper, brass, plastic (particularly cross-linked polyethylene called PEX, which is estimated to be used in 60% of single-family homes ), or other nontoxic material. Due to its toxicity , most cities moved away from lead water-supply piping by

7221-613: Was applied to milling grain, and powering lumber, machining and textile operations . Modern water turbines use water flowing through a dam to drive an electric generator . Windmill: Early windmills captured wind power to generate rotary motion for milling operations. Modern wind turbines also drives a generator. This electricity in turn is used to drive motors forming the actuators of mechanical systems. Engine: The word engine derives from "ingenuity" and originally referred to contrivances that may or may not be physical devices. A steam engine uses heat to boil water contained in

7308-483: Was long a lower-cost alternative to copper before the advent of durable plastic materials but special non-conductive fittings must be used where transitions are to be made to other metallic pipes (except for terminal fittings) in order to avoid corrosion owing to electrochemical reactions between dissimilar metals (see galvanic cell ). Bronze fittings and short pipe segments are commonly used in combination with various materials. The difference between pipes and tubes

7395-456: Was the inclined plane (ramp), which has been used since prehistoric times to move heavy objects. The other four simple machines were invented in the ancient Near East . The wheel , along with the wheel and axle mechanism, was invented in Mesopotamia (modern Iraq) during the 5th millennium BC. The lever mechanism first appeared around 5,000 years ago in the Near East , where it

7482-482: Was the favoured material for water pipes for many centuries because its malleability made it practical to work into the desired shape. Such use was so common that the word "plumbing" derives from plumbum , the Latin word for lead. This was a source of lead-related health problems in the years before the health hazards of ingesting lead were fully understood; among these were stillbirths and high rates of infant mortality . Lead water pipes were still widely used in

7569-491: Was used in a simple balance scale , and to move large objects in ancient Egyptian technology . The lever was also used in the shadoof water-lifting device, the first crane machine, which appeared in Mesopotamia c.  3000 BC , and then in ancient Egyptian technology c.  2000 BC . The earliest evidence of pulleys date back to Mesopotamia in the early 2nd millennium BC, and ancient Egypt during

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